Many techniques, approaches and systems have been established for the reconstruction of service load histories for vibration simulation tests. For example, aircraft and space launch vehicle structures must be tested under different aerodynamic and engine thrust loads, automobiles and other ground vehicles must be tested under ground and engine vibration loads. The success of a random vibration simulation test heavily depends on how accurately service loads can be produced in a laboratory. Many sophisticated and very expensive systems have been developed for these kinds of simulation tests. However, because of high cost and complexity, the usage of these systems is limited. The five commonly recognized ones are: constant amplitude load histories, programmed load histories, service duplication, random load spectrum, and remote parameter control. The service load histories generated by using the first two techniques are very inaccurate. The third technique is rarely used because the testing duration should be the same as the product service life and it also usually requires that the structure to be tested be exactly the same as the structure that is used to record the original service loads. The last two techniques require very expensive systems to generate service loads but loads generated do not fully represent the real service loads. Also, for most mechanical systems, the service life is much longer than the testing duration. Accelerated tests therefore are needed. However, with all current approaches, it is almost impossible to obtain an accurate acceleration rate when an accelerated test is conducted.
The present invention overcomes the limitations of the previous methods. With this invention, accurate service load histories can be generated and the relationship (acceleration rate) between the times for an accelerated test and for original service can be identified. A high fidelity simulation test therefore can be conducted with much less time and cost.